Apparatus for drying material



5, 1935. s; KIESSKALT 1,993,062

I APPARATUS FOR DRYING MATERIAL Filed Oct. 22, 1932 11 n O0 (Raf; P

INVENTOR 2 ATTORNEYS.

Patented Mar. s, 1935 l. 1,993,062

UNITED STATES PATENT OFFICE- APPARATUS FOR DRYING MATERIAL Siegfried Kicsskalt, Frankiort-on-the-Main- Hochst, Germany, alllgnor to Bcnno Schildo laleaschinenban Akticngesellschaft, Hersi'eld,

rmany Application October 22, 1932, Serial No. 639,095

In Germany Novemberv 2, 1931 2 Claims. (CI. 3419) The present inventionrelates to a process for circulating air, subdivided by the partition M drying material, which comprises exposing the into the two chambers B and G. B is the chammaterial to be dried to the action of a current'of her into which the car C provided with plates air or another gas, the'drying process being perfor the reception of the material to be dried is formed in a room subjected to periodical changes introduced. A ventilator D is placed within the 5 0f the pressure of air or gas, and an apparatus heating chamber G, the plane of revolution of for executing this process. the ventilator is between the two air changing In most of the drying installations to be used flaps K and L and the two openings N and O in in industry, such as drying chambers with cirthe partition M. This ventilator moves the air culating air, roller driers,driers provided with inthe direction of the arrow, the airbeing heated 10 mechanical conveying installations, the drying by the heating device E. Ata suitable place a effect is based upon the fact that the moist air, revolving flap F is mounted, which periodically produced at the surface of the material to be interrupts the circulating current of air. If the dried due to the evaporation or vaporip'ation, is flap F is in the situation (1) marked by broken is absorbed by the not completely saturated part lines, the usual circulation of air takes place. In of the air and then eliminated, and that the moissituation (2), i. e. if the flap F is shut, the venture contained within the material gradually tilator reduces the atmospheric pressure in the follows due to the porosity and diifusing action of room B to an extent which is determined by the the material. Hence it results that the eflective size of the rooms in'front of and behind the rate of decrease in diffusion, which by itself is ventilator, its sp ed and i efflciency- At the 20 very small, is not supported by any convective same time the pressure in the chamber G intransversal motion of'air within the material. creases, this being, however, without any im- The long dryingperiods are due to these facts, portance for the manner of action of the appa- I have now found that the drying process can ratus. On account of the decreasing Pressure i beaccelerated and the period of drying be shortthe chamber B, the a r hfl w moisture I ned by subjecting the air or another gas in the leaves the capillaries and cavities of the material drying apparatus to periodical fluctuations in to be dried until the reduced pressure has been pressure, thus causing within the pores of the compensated. The flap F then opens again,.the material to be dried a quick change of air or the pr ssur in the cham r 3 in e nd new so-other gas. This process can be applied in all heated air penetrates from the outside into the drying apparatus operating with or without cirpores of the material to be dried so that they culating air. The fluctuations of pressure may, are filled up again. The operation is then confor instance, be produced by any air conveying tinuously repeated. In order to attain the deinstallation. If the dr in is performed by means si d purp s it may e advisabl t aus t e of circulating air, the fluctuations may be proflap to revolve in an irregular velocity in order 35 duced by a mechanically operating shut-oil deto control the two p r A p device causvice which is inserted into the circulating curi s the fl p o op in certain pos vfor a rent of air. This shut-ofl' device may also have h rt ime may 1 be used- It y be i the form of a revolving flap. The ventilation tant to cause the fl p t p slowly so that the 40 in thedrying chambers may be performed by over-pressure in the chamber G is not compen- 40v mechanically controlled means which are suitsated too quickly, thus causing a strong current ably adjusted in such a manner that the pulsatof air to pass over the drying plates, by which ing action in the drying room is increased thereby. u n fin mat ria on h pla for instance A particular advantage .of the invention re.- dyestuffs, might be blown away. Instead of one sides in the fact that the usual apparatus, the flap the e may be used severa flaps idi 45 construction of which need not be strengthened, me b s, valves and S la d are sumcient, ii the pulsations are within the The openings through which the air or another scope of some hundred millimeters of water 001- drying gas is introduced into and removed from umn. The period of drying can be considerably the drying apparatus may be fitted so that they so shortened therewith. The present invention is, are controlled by flaps which likewise rotate,

however, not limited to these pressure intervals. thereby increasing the action of pulsation. For In the accompanying drawing a drying appainstance, in the drying apparatus illustrated in 'ratus according to the invention is diagrammatthe accompanying drawing the flap K for rem'ovically illustrated by a cros'ssection of the device. ing theair may be opened during the whole time In the drawing A is a usual drying room with or a part of the time when the flap F is shut, 5;

In all other driers filled with air the efiect above described is fundamentally the same.

It is understood that instead of air another gas, for instance nitrogen or carbonic acid, may also be used as the drying agent.

In the following claims by the term gas there is to be understood any gas, especially air, nitrogen or carbonic acid.

I claim:

1. An apparatus for drying material, which comprises an air-tight room subdivided into two chambers by means of a partition provided with two openings, a heating device for drying the air, two air changing flaps through which air may be introduced into and removed from one of these chambers, a ventilator within the same chamber, the plane of revolution of the ventilator bein between the two air changing flaps and the two openings in the partition, and a rotating flap closing one of the two openings in the partition and being provided with a device for alternately opening and shutting the flap.

2. An apparatus for drying material, which comprises a gas-tight room subdivided into two chambers by means of a partition provided with two openings, one of said chambers being provided with an inlet and an outlet for the circulating drying gas, a ventilator located in said chamber between said inlet and outlet and between said openings in the partition, a heating device located in said chamber between said inlet and the opening in the partition which is situated on the same side of the ventilator and a device for alternately opening and shutting this open- SIEGFRIEH) 

